From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.lixom.net (lixom.net [66.141.50.11]) by ozlabs.org (Postfix) with ESMTP id 412E1679F3 for ; Fri, 14 Apr 2006 01:57:37 +1000 (EST) Date: Thu, 13 Apr 2006 10:57:17 -0500 To: Muli Ben-Yehuda Subject: Re: [PATCH] [2/2] POWERPC: Lower threshold for DART enablement to 1GB, V2 Message-ID: <20060413155717.GF24769@pb15.lixom.net> References: <20060413020559.GC24769@pb15.lixom.net> <20060413022809.GD24769@pb15.lixom.net> <20060413025233.GE24769@pb15.lixom.net> <20060413064027.GH10412@granada.merseine.nu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20060413064027.GH10412@granada.merseine.nu> From: Olof Johansson Cc: Olof Johansson , linuxppc-dev@ozlabs.org, paulus@samba.org, linux-kernel@vger.kernel.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, Apr 13, 2006 at 09:40:27AM +0300, Muli Ben-Yehuda wrote: > On Wed, Apr 12, 2006 at 09:52:33PM -0500, Olof Johansson wrote: > > > iommu=off can still be used for those who don't want to deal with the > > overhead (and don't need it for any devices). > > I've been pondering walking the PCI bus before deciding to enable an > IOMMU and checking each device's DMA mask. Is this something that you > considered and rejected, or just something no one got around to doing? It's something I thought about, but right now we enable the IOMMU quite early during boot. It'd take a bit of surgery to shuffle things, and I decided that it's not worth the work (and risk of regressions) for 2.6.17. -Olof